This invention relates to a user programmable micro controller and more particularly to micro controllers used in devices requiring security such as IC cards and data banks.
In the conventional user programmable micro controllers, memory regions for programs such as the OS program installed when the micro controller was manufactured, and user programmable memory regions for programs made by the user after the micro controller was manufactured are separately provided.
However, because the program code made by the user is not checked, there is a possibility that programs and/or data in memory regions other than the user programmable memory regions could be damaged, read out or altered.